* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html,
body {
  width: 100%;
  min-height: 100vh;
}

#root {
  display: flex;
  flex-direction: column;
  /* align-items: flex-start; */
  width: 100%;
  min-height: 100vh;
  background: antiquewhite;
}

main {
  flex: auto;
  display: flex;
  justify-content: center;
  align-items: center;
}
header,
footer {
  height: 50px;
  background-color: aliceblue;
}

.btn {
  margin: auto;
  padding: 20px 0;
  width: 200px;
  position: relative;
  z-index: 1;
  color: #fff;
  /* background-color: #000; */
  background-color: transparent;
  /* outline: 4px solid #fff; */
  font-size: 24px;
  border-radius: 5px;
  border: 0;
  overflow: hidden;
}

.btn::before {
  content: '';
  background-color: red;
  position: absolute;
  width: 200%;
  height: 200%;
  z-index: -1;
  left: 50%;
  top: 50%;
  transform-origin: 0 0;
  animation: rotate 3s infinite linear;
}
.btn::after {
  content: '';
  position: absolute;
  background-color: rgba(0, 0, 0, 1);
  width: calc(100% - 6px);
  height: calc(100% - 6px);
  top: 3px;
  left: 3px;
  z-index: -1;
  border-radius: 5px;
}

@keyframes rotate {
  to {
    transform: rotate(1turn);
  }
}

img {
  aspect-ratio: 480/299;
}
